BMI Chart: How Much You Should Weigh at Your Height and Age (Supposedly)

People often want to know where they stand (health wise) based on a particular formula. They believe that staying within a certain numerical number based on a few qualifying factors means they are healthy. This formula is part of the BMI Index, a set of numerical statistics that display what a person should weigh at a particular height and age. Naturally, because it has been touted as “official” for a long time now, people believe that falling within that particular weight set that the BMI Index displays means everything is alright. However, that is the wrong way to think about the BMI Index. Health, and what your weight “should be” at a particular height and age, are separate concepts. Well, not entirely, but enough so to warrant stating that the BMI Index is simply a very generic ballpark estimate of anything relating to health. Here’s why:

Simply asking “how much should I weigh for my height and age” and checking the statistics on a numerical chart will give you an answer, but when dealing with something so complex (health), do you really expect the BMI Index to provide the right answer? You cannot quantify whether you’re healthy based on a numerical chart. At best, you can identify that there’s a problem if you’re grossly disproportionate. This is so because the BMI Index deals solely with weight, not health. Weight and health are popularly substituted for each other (which explains the BMI hype in the first place), but they are not one in the same. While weight is often an indicator of health, it is only one component in an overall analysis of whether an individual is healthy. You know this, after all, doctors would run out of business if we all determined our health based on a couple numbers, no?

With that said, even when it comes to predicting whether an individual is at the “appropriate” weight for their height and age, the BMI Index runs into problems. Yes, that’s right. It isn’t even great at what it is supposed to do. Now, this is largely due to the fact it is so simple. Its simplicity does not allow it to take into account very important factors. Here’s two of its most important limitations:

It completely ignores body fat percentage. Weight and fat are two different things. By not differentiating between muscle and fat, the BMI quickly can lead an individual astray. In fact, body fat percentage is one of the most, if not the most, important components of gauging potential health status. Ignoring it, the BMI Index creates this scenario: Individual #1 works out and weighs 180 lbs. at 10% body fat. Individual #2 lives a sedentary lifestyle and weighs 160 lbs. at 30% body fat. Imagine they are the same height and age. Individual #2, according to the BMI statistics, would be in a “healthier” weight range. Individual #1, while ripped, would apparently be overweight.

It ignores waist size. There would be more accuracy if individuals were told to measure their waist to hip ratios (weight/hip). This is also not ideal, but it would be a step forward. Men’s ratios should be around a .8 or .9, and women’s around a .7. Instead, as illustrated above, Individual #2 (highly likely to have a gut at that body fat percentage) is shown to be erroneously at a healthier weight.

Many individuals may claim that, even with these limitations in mind, the BMI Index is solid because it is appropriate for the majority of the population. The majority does not fall into the athlete/weight-lifter category and, after all, those are really the only people who will have false readings using the index. Although it is true that the average individual will not stray much from the pack, the BMI Index falsely assumes a very low level of muscle mass and a high level of body fat when coming up with its weight ranges. Therefore, even within the non-active crowd, there is much room for variation that the simplicity of the BMI Index doesn’t acknowledge. This skews the results for anybody.

With all that said, the BMI Index is not entirely useless. If someone understands its limitations, it can provide an individual with a quick answer to this common question. It will be a generic estimate, but it can at least provide someone with a way to gauge if there’s trouble looming because the resulting numbers are far removed from the BMI chart. The key, however, is not to simply rely on it as if it answers all the questions. Use it as a tool in your arsenal, nothing more. Good Luck!

Calculating BMI:

Recommendations:

Below 18.5 (Underweight)

18.5 to 24.9 (Ideal)

25.0 to 29.9 (Overweight)

30.0 and above (Obese)

Formula: Take your weight (in pounds), divide it by the square of your height (in inches), and multiply the total by 703 (for conversion purposes). As an example we’ll use a 180 pound 6’0 individual: